Experimental discussion on inductive type contactless power transfer system with boost or buck converter connected to rectifier

Contactless power transfer is expected to be applied to many applications since it is convenience and safety. Inductive power transfer (IPT) is a kind of contactless power transfer schemes uses two coils. These coils are inductively coupled and power is transferred from primary coil to secondary coil when high frequency (a few tens of kHz) AC power supplies to primary coil. In many applications using IPT, received AC power is converted to DC power and then the power is charged to battery. Thus, two functions which are rectification and regulating voltage or current are required on the receiver (secondary) side. In this study, one of two types (buck type and boost type) of DC-DC converter connected to diode rectifier were applied to IPT system, and characteristics of each type were compared by experiments. As a result of the experiments, it was found that both rectifiers have two functions which are rectification and regulating voltage or current. It was also found that boost type is better in terms of regulation capability and of efficiency of resonant circuit.